CN114901078A

CN114901078A - Process for preparing a liquid coffee concentrate with reduced acrylamide content by resin treatment

Info

Publication number: CN114901078A
Application number: CN202080088564.9A
Authority: CN
Inventors: 格特詹·海曼; 瑞贝卡·范·德·韦斯顿·斯科格沃尔德; 伊恩·布朗尼; 艾伦·罗斯
Original assignee: Royal Multidimensional Egbertus Co ltd
Current assignee: Royal Multidimensional Egbertus Co ltd
Priority date: 2019-12-20
Filing date: 2020-12-18
Publication date: 2022-08-12
Also published as: EP4075996A1; JP2023507193A; BR112022012200A2; GB2591988A; MX2022007648A; GB201919065D0; CA3163487A1; AU2020407861A1; KR20220107228A; GB2591988B; US20230023081A1; WO2021123161A1

Abstract

A process for producing a liquid coffee concentrate having a reduced acrylamide content is disclosed. The method involves contacting a low aromatic aqueous coffee extract with a carbon and/or silica-based resin having adsorption functionality to reduce the acrylamide content of the extract prior to combining the treated extract with a high aromatic aqueous coffee extract. In particular, the method comprises the steps of: a) providing a low aromatic aqueous coffee extract having a first acrylamide content; b) providing a high aromatic aqueous coffee extract; c) contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function to provide a low aromatic aqueous coffee extract having a second acrylamide content; and d) combining the low aromatic aqueous coffee extract having a second acrylamide content with the high aromatic aqueous coffee extract to provide a liquid coffee concentrate, wherein the second acrylamide content is lower than the first acrylamide content.

Description

Process for preparing a liquid coffee concentrate with reduced acrylamide content by resin treatment

The present invention relates to a process for producing a liquid coffee concentrate with a reduced acrylamide content. The method involves contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having adsorption functionality to reduce the acrylamide content of the extract prior to combining the treated extract with the high aromatic aqueous coffee extract. The present invention also relates to a liquid coffee concentrate with reduced acrylamide content produced according to the process disclosed herein. The present invention also provides soluble coffee prepared by freeze or spray drying a liquid coffee concentrate having a reduced acrylamide content. Finally, the present invention provides the use of a carbon and/or silica based resin with adsorption function for reducing the acrylamide content of a low aromatic aqueous coffee extract.

It is well known to extract roast and ground coffee with water to obtain a liquid coffee concentrate of high coffee solids. Furthermore, it is well known to dry such concentrates by spray drying or freeze drying to obtain soluble beverage products. The liquid coffee concentrate and soluble beverage product may then be reconstituted with hot water at the convenience of the consumer to obtain a coffee beverage. Industrial production of liquid coffee concentrates is associated with higher temperatures and pressures than coffee shop brewing systems. This allows higher yields and therefore profitability from coffee beans, but has the side effect that the coffee may adopt undesirable process flavour notes.

Recently, it has been found that food products that are subjected to high temperatures during processing often contain high levels of acrylamide. For example, it has been found that during the first minute of the roasting process, the highest amount of acrylamide is formed in the coffee beans. Since acrylamide is a potential carcinogen, there is a need in the food industry to strive to reduce the level of acrylamide in foods. Therefore, it is desirable to take measures to reduce the level of acrylamide that accumulates during coffee production.

EP0363529 discloses a method for obtaining increased yield when obtaining coffee extract from roast and ground coffee beans. In particular, the process focuses on hydrolyzing partially extracted coffee at high temperatures in a short processing time. WO2013/005145 discloses a method for reducing the level of acrylamide in roasted coffee, the method comprising reducing the level of asparagine and reducing the level of aspartic acid in unroasted coffee. WO2017/004715 discloses the development of asparagine-reducing yeast by adaptive evolution and its use to reduce acrylamide formation.

The reduction of acrylamide in coffee can be achieved by reducing or eliminating the level of asparagine (the precursor required to form acrylamide). US7220440 describes such a method of reducing the level of asparagine in unroasted coffee beans, which method comprises adding an asparagine-reducing enzyme, such as asparaginase, to the unroasted coffee beans. This reduces the level of asparagine, and subsequently reduces acrylamide formation upon baking. The method utilizes enzymatic treatment of unroasted coffee beans. However, this approach often results in "off-flavors," which can have a negative impact on the overall aroma and flavor characteristics of the final coffee product. Furthermore, the non-immobilized enzyme may be inadvertently and inadmissibly retained in the final coffee product.

Recently, it has been shown that acrylamide can be removed directly from coffee extracts obtained from roasted coffee beans. EP3254568 describes the use of an adsorption resin for reducing acrylamide in liquid coffee extracts or soluble coffee. In this process, a liquid coffee extract is passed through a bed of cationic adsorption resin to effect a reduction in the acrylamide content. This approach avoids some of the problems associated with enzyme activity on unroasted coffee beans. However, the production of coffee with specific aroma and flavor characteristics is an accurate and complex process, and any additional processing steps can adversely affect the characteristics of the final coffee product. Thus, treatment of the liquid extract with the adsorption resin may alter the aroma components present in the extract and may therefore negatively affect the taste of the final coffee product.

Accordingly, it would be desirable to provide an improved method for preparing a liquid coffee concentrate or soluble coffee, an improved coffee product and/or to address at least some of the problems associated with the prior art, or at least to provide a commercially viable alternative. It is therefore an object of the present invention to provide a process for producing a liquid coffee concentrate or soluble coffee with a reduced acrylamide content, which process has a lower impact on the aroma and flavor characteristics of the final coffee product compared to the prior art.

The present inventors have determined that acrylamide reduction may be performed at various stages of the extraction process. In particular, the inventors have found that by performing acrylamide reduction on coffee extracts having a significant acrylamide content but importantly having few aroma components, aroma and flavor losses can be reduced. The method involves obtaining a high aroma extract from roast and ground coffee by an aroma restoration process to preserve volatile flavor components. The pre-extracted roast and ground coffee is then extracted to produce a low aromatic aqueous coffee extract. Acrylamide reduction was only performed on this low aromatic extract. Thus, the acrylamide reduction step has a lower impact on the overall aroma and flavor profile of the total extract compared to the prior art. Once processed, the low aromatic coffee extract may be combined with the preserved aroma and flavor components in the high aromatic extract to produce a liquid coffee concentrate.

The present invention has a number of advantages over prior art methods, as will become apparent from the discussion below. An advantage of the process of the present invention is that the resulting coffee concentrate has a reduced level of acrylamide, while having a lower impact on the aroma and flavor characteristics of the final product than observed in the prior art. In particular, by subjecting only the low aromatic extract to the acrylamide reduction step, only a certain percentage of the total extract is treated and therefore the interference with the characteristics of the final coffee product is less. Furthermore, by restoring the aroma components before the acrylamide reduction step is performed, most of the desired aroma compounds are retained and thus acrylamide can be removed with less impact on the quality of the resulting coffee product compared to the prior art.

In a first aspect, the present invention provides a method for producing a liquid coffee concentrate, the method comprising the steps of:

a) providing a low aromatic aqueous coffee extract having a first acrylamide content;

b) providing a high aromatic aqueous coffee extract;

c) contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function to provide a low aromatic aqueous coffee extract having a second acrylamide content; and

d) combining a low aromatic aqueous coffee extract having a second acrylamide content with a high aromatic aqueous coffee extract to provide a liquid coffee concentrate,

wherein the second acrylamide content is lower than the first acrylamide content.

By "liquid coffee concentrate", it is meant a concentrated solution comprising soluble coffee solids, suitable for dilution to obtain a coffee beverage at conventional solids levels. Liquid coffee concentrates are usually sold as so-called bag-in-box products for dilution in vending machines to obtain coffee beverages. The liquid coffee concentrate comprises from 6 wt% to 80 wt% coffee solids, preferably from 10 wt% to 65 wt%, more preferably from 15 wt% to 50 wt% coffee solids.

An "aqueous coffee extract" is a solution comprising soluble coffee compounds. These are obtained by contacting roasted and ground coffee beans with water, usually hot water or steam. Depending on the temperature and pressure used for extraction, the yield of soluble coffee compounds obtained from roast and ground coffee will vary. High temperatures result in high yields, hydrolyzing complex carbohydrates in roast and ground coffee into soluble components. While high yields are clearly desirable for commercial production, they also result in the production of undesirable flavors and extraction of acrylamide.

The "low aromatic aqueous coffee extract" may be characterized based on the chemical components present in the extract. For example, a low aromatic aqueous coffee extract may be considered an extract having a ratio of 2, 3-butanedione to ethylguaiacol of less than 30: 1. Such extracts are commonly referred to as secondary extracts. Similarly, the highly aromatic aqueous coffee extract may be characterized by a ratio of 2, 3-butanedione to ethylguaiacol of greater than 30: 1. Preferably, the ratio of 2, 3-butanedione to ethylguaiacol in the low aromatic extract is at most half that in the high aromatic extract (e.g., 20:1 in the low aromatic extract versus 40:1 in the high aromatic extract), more preferably at most one third, more preferably at most one fourth.

Preferably, the low aromatic aqueous coffee extract having a first acrylamide content is obtained by aqueous extraction of dearomatized roast and ground coffee. By "dearomatized roast and ground coffee", it is meant that the roast and ground coffee has been previously subjected to at least one primary extraction step, such as extraction in water at a temperature of from 100 ℃ to 170 ℃, preferably from 120 ℃ to 150 ℃. Alternatively or in addition, the dearomatized roast and ground coffee may be obtained by subjecting the roast and ground coffee to an aroma restoration process, such as an aroma restoration process involving contacting the roast and ground coffee with steam. Such aroma restoration methods provide a highly aromatic aqueous coffee extract from steam. Dearomatized roast and ground coffee is also produced in the aroma restoration process.

Preferably, the low aromatic aqueous coffee extract having a first acrylamide content is obtained by aqueous extraction of dearomatized roast and ground coffee, whereby the aqueous extraction is carried out at a temperature of 140 ℃ to 230 ℃, preferably 160 ℃ to 200 ℃, preferably 160 ℃ to 195 ℃. If the coffee has been subjected to a primary extraction step, this will be considered a secondary coffee extract. Residence times at such temperatures are typically from 1 minute to 30 minutes. The resulting dearomatized roast and ground coffee is commonly referred to as "spent coffee".

In a more preferred embodiment, the aqueous extraction is carried out at a temperature above 200 ℃, preferably from 200 ℃ to 260 ℃, preferably from 210 ℃ to 230 ℃ using spent coffee that provides a low aromatic aqueous tertiary coffee extract. That is, because the extraction is performed on the spent coffee produced by the secondary extraction step, it is considered to be a tertiary extract. As will be appreciated, each of the primary, secondary, and tertiary steps involve more severe extraction conditions. In certain embodiments, the aqueous extraction is performed at a temperature between 220 ℃ and 240 ℃. In certain embodiments, the aqueous extraction is performed at a temperature above 221 ℃. Residence times at such temperatures are typically from 1 minute to 15 minutes. Such high temperatures are associated with high yields and the production of undesirable off-flavors and acrylamide levels.

For the avoidance of doubt, the primary coffee extract is obtained by aqueous extraction of roasted coffee beans that have not been previously extracted (or have only been subjected to an aroma restoration step). The secondary coffee extract is obtained by aqueous extraction of roasted coffee beans previously extracted with hot water. The tertiary coffee extract is obtained by aqueous extraction of roasted coffee beans which have been extracted twice with hot water in advance. The extraction conditions (i.e., temperature) generally increase with each of the primary, secondary, and tertiary extraction steps.

The low aromatic aqueous coffee is typically a secondary extract or a tertiary extract or a combination of both. In one embodiment, the low aromatic aqueous coffee extract having the first acrylamide content is a mixture of a secondary coffee extract and a tertiary coffee extract.

Preferably, contacting the low aromatic aqueous coffee extract with the carbon and/or silica-based resin having an adsorption function comprises flowing the low aromatic aqueous coffee extract through a bed comprising the carbon and/or silica-based resin having an adsorption function. This ensures a high surface area for the treatment of soluble coffee solids in the extract.

Preferably, the carbon and/or silica-based resin having an adsorption function is a monolithic dioxideSilicon, anion/cation exchangers or size exclusion resins with affinity for molecules with dipoles. Preferably, the resin comprises a surface area between 700m ² G and 1500m ² A/g, preferably between 900m ² G and 1500m ² Between/g, more preferably about 1200m ² Per gram of particles. Preferably, the resin comprises a pore volume of between 0.08cm ³ G and 0.2cm ³ Between/g, preferably about 0.15cm ³ Per gram of particles.

In certain embodiments, the second acrylamide content is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or 100% less than the first acrylamide content.

In certain embodiments, both the low aromatic aqueous secondary coffee extract and the low aromatic aqueous tertiary coffee extract may be treated according to the first aspect of the invention by contacting the aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function and flowing the aqueous coffee extract through a bed comprising the carbon and/or silica-based resin having an adsorption function.

In certain embodiments, only the low aromatic aqueous secondary coffee extract or alternatively only the low aromatic aqueous tertiary coffee extract may be treated according to the first aspect of the invention by contacting the aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function and flowing the aqueous coffee extract through a bed comprising the carbon and/or silica-based resin having an adsorption function.

In a second aspect, the present invention provides a liquid coffee concentrate or a soluble coffee product obtainable according to the method described in the first aspect. The product is characterized by having a more robust processed coffee extract (i.e., higher yield) with the extraction characteristics of low levels of acrylamide.

Preferably, the method further comprises the step of concentrating the low aromatic aqueous coffee extract having the second acrylamide content. Low solids content can be associated with higher extraction yields from coffee beans, but higher solids are required to obtain useful products.

Alternatively, the method further comprises the steps of: drying, thereby producing a soluble coffee product.

Preferably, the method further comprises regenerating the waste resin. This allows the process to be carried out on a continuous basis.

In certain embodiments, the liquid coffee concentrate or soluble coffee product has a reduced acrylamide level of 2 wt% to 50 wt%. Acrylamide levels can be measured by liquid chromatography techniques (LC) and Mass Spectrometry (MS) as detection methods using electrospray ionization (LC-ESI-MS/MS), and are measured based on the dry weight of the relevant extract.

The coffee product is preferably prepared by combining an untreated primary extract with a treated secondary extract and/or tertiary extract. The ratio of treated extract to untreated extract in the product will affect the level of acrylamide reduction observed. The higher the proportion treated, the lower the acrylamide content. However, the greater the proportion of treatment, the greater the difference in product from the original flavor.

In a third aspect, the present invention provides the use of a carbon and/or silica based resin having an adsorption function selective for acrylamide for reducing the acrylamide content of a low aromatic aqueous coffee extract.

Detailed Description

The invention will now be further described. In the following paragraphs, the different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any one or more other aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

A.Method for producing a liquid coffee concentrate

The present invention is based on the following findings: it is particularly advantageous to subject the low aromatic aqueous coffee extract to an acrylamide reduction step. The extract is typically obtained from roast and ground coffee beans that have previously been subjected to at least an aroma restoration process and a primary extraction process. A low aromatic aqueous coffee extract may be obtained from such dearomatized roast and ground coffee. Subsequently, the low aromatic aqueous coffee extract is passed through a bed comprising carbon and/or silica-based resins having an adsorption function in order to remove acrylamide from the extract. As explained elsewhere herein, the carbon and/or silica-based resin having an adsorption function has a microporous physical structure that allows selective adsorption of polar organic substances and/or ions. Carbon and/or silica-based resins having an adsorption function selective for acrylamide may be used to selectively extract acrylamide from aqueous coffee extracts.

According to a first aspect of the present invention, a method for producing a liquid coffee concentrate is provided. The method comprises the following steps:

b) providing a high aromatic aqueous coffee extract;

d) mixing the low aromatic water-based coffee extract with a second acrylamide content

Combined with a high aromatic aqueous coffee extract to provide a liquid coffee concentrate,

The method comprises a number of steps. It will be apparent that a plurality of these steps must be performed sequentially, but it will also be understood that these steps may be performed as part of a continuous process, batch, or a combination of both.

i.Roast and ground coffee

According to step (step a) of the method, a low aromatic aqueous coffee extract having a first acrylamide content is provided. According to a further step of the process (step b), a highly aromatic aqueous coffee extract is also provided. The coffee extract may be obtained from green coffee beans that have been roasted and ground using art-recognized techniques. The green coffee beans may be a mixture of different types of coffee beans. For example, the green coffee beans may be a mixture of arabica coffee and robusta coffee. The method of grinding roasted coffee beans requires a compromise to be sought between obtaining the largest possible surface area of the ground coffee beans and obtaining the lowest possible pressure drop over the extraction chamber. Typically, the ground coffee beans have an average size of at most 2.0 millimeters.

ii.Aroma recovery method

In order to better preserve coffee aroma, the acrylamide reduction step (step c) of the present invention is performed on a low aromatic aqueous coffee extract. This avoids the loss of the desired aroma of the carbon and/or silica-based resin having an adsorption function and also reduces the volume of the extract to be treated.

Such a low aromatic aqueous coffee extract having a first acrylamide content is obtained by subjecting roast and ground coffee to an aroma restoration process and optionally a primary extraction, and subjecting the remaining dearomatized roast and ground coffee to an extraction step. The aroma restoration process provides a highly aromatic aqueous coffee extract that can be stored for later use, as well as dearomatized roast and ground coffee that can be used for extraction. Thus, aroma restoration is performed on the roast and ground coffee before the start of the extraction process on the dearomatized and/or used roast and ground coffee, so that the most volatile and desired aroma is restored. The resulting aroma-rich vapor is condensed and stored under cooling conditions for subsequent combination with the treated low aromatic aqueous extract. Thus, the method of producing a liquid coffee concentrate comprises subjecting roast and ground coffee to an aroma restoration process to obtain: (i) a highly aromatic aqueous coffee extract; and (ii) dearomatized roast and ground coffee.

Examples of flavor recovery include steam stripping, or supercritical CO ₂ And (4) extracting. Preferably, the aroma restoration process involves contacting roast and ground coffee with steam to strip any aroma from the coffee, followed by restoration of aroma from the steam as a highly aromatic aqueous coffee extract. Preferably, the aroma restoration step is performed under vacuum. At a certain pointIn some embodiments, the aroma restoration method involves contacting roast and ground coffee with steam and restoring a highly aromatic aqueous coffee extract from the steam.

As known to the skilled person, a high aromatic coffee extract differs by itself from a low aromatic coffee extract in that it has a rather high amount of volatile flavour compounds compared to semi-volatile flavour compounds. Such compounds are known, for example, from Clarke R.J. and Vitzthim O.G. (Coffee recovery Developments,2001, ISBN 0-632-05553-7, page 71, Table 3.3). As is evident from the table, in one aspect, propionaldehyde, methylpropionaldehyde and 2, 3-butanedione are measurable volatile flavor compounds. Pyrazine compounds and guaiacol compounds, on the other hand, are semi-volatile flavor compounds. Taking 2, 3-butanedione as an example of volatile coffee flavor compounds and ethylguaiacol (4-ethyl-2-methoxyphenol) as an example of semi-volatile coffee flavor compounds, when these compounds are 2, 3-butanedione to ethylguaiacol in a weight/weight ratio of greater than 30 in a particular coffee extract, the extract may be described as a high aromatic coffee extract. Thus, the low aromatic coffee extract has a weight/weight ratio of 2, 3-butanedione to ethylguaiacol of less than 30.

iii.Extraction of

The low aromatic aqueous coffee extract may be obtained by any known extraction technique. For example, the aqueous extract may be prepared by extracting coffee through a counter-current percolator. The low aromatic aqueous coffee extract may be obtained by aqueous extraction of dearomatized roast and ground coffee.

For example, in certain embodiments, dearomatized roast and ground coffee is subjected to one or more aqueous extraction steps to produce one or more aqueous coffee extracts. Dearomatized roast and ground coffee can be subjected to multiple extraction steps to produce multiple extracts. The dearomatized roast and ground coffee may be subjected to aqueous extraction at temperatures above 100 ℃. Preferably, the dearomatized roast and ground coffee is subjected to aqueous extraction at a temperature above 140 ℃. Residence times at such temperatures are typically from 1 minute to 30 minutes. In a more preferred embodiment, the aqueous extraction is carried out at a temperature above 200 ℃, preferably between 200 ℃ and 260 ℃. In certain embodiments, the aqueous extraction is performed at a temperature between 220 ℃ and 240 ℃. In certain embodiments, the aqueous extraction is performed at a temperature above 221 ℃. Residence times at such temperatures are typically from 1 minute to 15 minutes, preferably from 3 minutes to 13 minutes, more preferably from 3 minutes to 8 minutes. Preferably, extracting the dearomatized roast and ground coffee provides a low aromatic aqueous coffee extract having at least a first acrylamide content. The low aromatic aqueous coffee extract is preferably a secondary coffee extract and/or a tertiary coffee extract as described herein. It is this low aromatic aqueous coffee extract having a first acrylamide content which is subjected to an acrylamide reduction step (step c).

Due to the high temperatures employed during the extraction process, in particular by providing a tertiary extract above 200 ℃, the pressure in the reactor can vary. Thus, in certain embodiments, the aqueous extraction is carried out at a pressure of about 5 atmospheres to 20 atmospheres, preferably 17 atmospheres to 14 atmospheres. Since high temperatures may negatively affect the overall flavor and aroma characteristics of coffee, it is desirable to control the reaction time within a specified period of time with high reliability.

The dearomatized roast and ground coffee may be subjected to an initial aqueous extraction (primary extraction) at a temperature below 170 ℃ to obtain a primary aroma-rich extract. Preferably, the initial aqueous extraction is carried out at a temperature of from 100 ℃ to 170 ℃, more preferably from 140 ℃ to 170 ℃. This initial extraction step produces an additional aqueous coffee extract that can be stored with the restored high aromatic aqueous coffee extract. The aroma-rich extract can be stored while the acrylamide reduction step (step c) is performed on the low aromatic aqueous coffee extract before combining the separate extracts. In certain embodiments, the initial extraction step produces an additional aqueous coffee extract that can be combined with the high aromatic aqueous coffee extract and the low aromatic aqueous coffee extract having the second acrylamide content.

In a preferred embodiment, the aqueous extraction is preferably performed as a separate extraction. Methods for separation and extraction are known. Reference in this respect is WO 2007/043873. In a separate extraction process, roast and ground coffee is subjected to a primary extraction with water, thereby obtaining a primary aroma-rich extract having an extraction factor of at most 2.5, preferably at most 2.0, more preferably at most 1.5 and most preferably at most 1.0. Thereafter, a second primary extract is optionally obtained. Preferably, the water-coffee ratio is between 5.0 and 15. More preferably, the water-coffee ratio is lower than 10, and most preferably, the water-coffee ratio is between 6.5 and 8.5.

The term "extraction factor" is understood to mean the ratio of the mass of extract to the mass of dry roast and ground coffee in the primary extraction chamber. In practice, this extraction factor is determined by a compromise between, on the one hand, the sufficiency of the recovery of coffee aroma in the first primary extract and, on the other hand, the lowest possible volume of the first primary extract. The extraction factor of this substance depends on the coarseness or degree of grinding of the roasted coffee, the number of extraction chambers and, in particular, percolators placed in series, the water-coffee ratio, the cycle time, the temperature of the feed water and the desired concentration of the final product, etc.

In the embodiment of the separate extraction in which the second primary extract is recovered from the primary extraction chamber, this additional extraction is also carried out in the primary extraction chamber after the extraction and storage of the first primary extract.

The main extracted, roasted, ground coffee is then fed to a further extraction section, where a subsequent extract (low aromatic aqueous coffee extract) is obtained. Optionally, a second primary extract may be added to the subsequent extract. Optionally, the main extracted, roasted, ground coffee may be subjected to multiple extraction steps to produce multiple subsequent extracts.

The first extraction and the subsequent extraction can be carried out in a conventional extraction chamber. In a preferred embodiment, both the first and subsequent extractions are performed in percolators or percolators placed in series. In particular, the subsequent extraction is advantageously carried out in at least 2, preferably at least 4 percolators connected in series. Typically, the number of percolators used in the primary extraction section is at least 0.5, which means that the percolators are connected in the primary extraction section during 50% of the cycle time. Preferably, at least 1 or 2 percolators are connected in the primary extraction section.

In embodiments wherein the dearomatized roast and ground coffee has been subjected to multiple extraction steps, the coffee extracts provided in steps a) and b) may be obtained by separating the multiple extracts into a low aromatic aqueous coffee extract and a further high aromatic aqueous coffee extract, respectively.

iv.Low aromatic aqueous coffee extract

The low aromatic aqueous coffee extract having a first acrylamide content is an undiluted or unconcentrated extract. Typically, the dry matter solids content of the extract is 15 wt% or less, preferably 2 to 10 wt%. Preferably, the acrylamide reduction step (step c) is performed on the concentrated extract, i.e. 15 to 60 wt% dry matter solids.

Most preferably, the low aromatic aqueous coffee extract subjected to the acrylamide reduction step (step c) is an extract with low aroma components and showing a substantial acrylamide content. Preferably, the low aromatic aqueous coffee extract has a high acrylamide content compared to the acrylamide content of other extracts obtained in the extraction process. Preferably, the low aromatic aqueous coffee extract having the first acrylamide content contains more than 10% of the total amount of acrylamide present in all extracts obtained in the extraction process. Preferably, the low aromatic aqueous coffee extract having the first acrylamide content contains more than 20% of the total amount of acrylamide present in all extracts obtained in the extraction process.

v.Reduction of acrylamide

According to the present invention, a low aromatic aqueous coffee extract is contacted with a carbon and/or silica-based resin having an adsorption function. Contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function to provide a low aromatic aqueous coffee extract having a second acrylamide content.

Adsorption and ion exchange are adsorption processes in which some adsorbate is selectively transferred from the fluid phase to the surface of insoluble rigid particles, which may be suspended in a container or packed in a column. The carbon and/or silica-based resin having an adsorption function used in the present invention is selective to acrylamide. It will be appreciated that carbon and/or silica based resins having an adsorption function will retain acrylamide due to the affinity of the resin for acrylamide molecules.

In particular, microporous resins useful in the present invention are of the size separation or exclusion type, wherein mixtures of compounds can be separated by molecular size. Smaller hydrophobic molecules are more easily trapped in the pores of the resin and thus smaller molecules are adsorbed onto the surface. Molecules that are too large will not penetrate the pores and will bypass the resin bed.

The appropriate adsorbent resin is selected according to the molecule to be removed. There are different kinds of adsorption resins, which differ by a specific hydrophobic capacity, and by a specific size and volume of the pores. It is to be understood that any carbon and/or silica based resin having an adsorption function may be used in the present invention, provided that it is suitable for adsorbing and/or separating acrylamide from an aqueous coffee extract. The molecular weight of the acrylamide molecule is 71.08 g/mol. This molecular weight value is much less than the value of soluble solids in a low aromatic aqueous coffee extract and therefore acrylamide molecules will be captured by the pores and adsorbed to the resin. The remaining extract containing soluble coffee solids will bypass the resin and can be collected.

The preferred embodiment is

AF5。

The surface area provided by the microporous resin determines the adsorption capacity of the resin. Carbon and/or silica-based resins having an adsorption function suitable for the purposes of the present invention are resins comprising a surface area of between 700m ² G and 1500m ² Microporous adsorbent of particles between/g. In certain embodiments, the ion exchange resin and/or adsorbent comprises a surface area between900m ² G and 1500m ² Particles between/g. Preferably, the adsorbent or porous ion exchange resin comprises a surface area of about 1200m ² Per gram of particles.

Alternatively or additionally, the carbon and/or silica based resin with adsorption function comprises a pore volume of between 0.08cm ³ G and 0.2cm ³ Particles between/g. Preferably, the carbon and/or silica-based resin having an adsorption function comprises a pore volume of about 0.15cm ³ Per gram of particles.

According to the invention, the step of contacting the low aromatic aqueous coffee extract having a first acrylamide content with a carbon and/or silica-based resin having an adsorption function (step c) produces a low aromatic aqueous coffee extract having a second acrylamide content. Importantly, according to the present invention, the second acrylamide level is lower than the first acrylamide level. In other words, the amount of acrylamide in the low aromatic aqueous extract decreases after contact with the carbon and/or silica-based resin having an adsorption function. In certain embodiments, the second acrylamide content is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or 100% less than the first acrylamide content. The acrylamide content of the low aromatic water-based coffee extract after contact with the resin is lower than the acrylamide content of the low aromatic water-based coffee extract before contact with the resin. In a particularly preferred embodiment, acrylamide is not present in the low aromatic aqueous coffee extract after contact with the carbon and/or silica based resin having an adsorption function. Thus, in certain embodiments, the low aromatic aqueous coffee extract having the second acrylamide content does not comprise any acrylamide.

The method may comprise flowing the low aromatic aqueous coffee extract through a bed comprising a carbon and/or silica based resin having an adsorption function. Thus, in other embodiments, the method entails flowing the low aromatic aqueous coffee extract through a bed comprising carbon and/or silica-based resins having an adsorption function for a time sufficient to produce a low aromatic aqueous coffee extract having a second acrylamide content that is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or 100% less than the first acrylamide content of the low aromatic aqueous coffee extract.

At least 50 vol/vol%, more preferably 75 vol/vol%, most preferably 100% of the low aromatic aqueous coffee extract is contacted with a carbon and/or silica based resin having an adsorption function.

In embodiments where the column is packed with a carbon and/or silica-based resin having an adsorption function, the column must be of sufficient size and length to effectively reduce or eliminate acrylamide from the aqueous coffee extract passing through it.

Over time, the contaminant ions and/or molecules bind to all available sites in the resin. Once the resin is exhausted, it must be recovered for further use by so-called resin regeneration. During regeneration, adsorption is substantially reversed by applying a concentrated regenerant solution. The regenerant may be a salt, acid or caustic solution depending on the type of resin and the application at hand. As the regeneration cycle progresses, the resin releases adsorbed ions and organic molecules, exchanging them for ions present in the regenerant solution. The eluted ions/molecules can be removed and disposed of. In most cases, the resin is flushed to remove any residual regenerant before the resin is reused. Thus, in another embodiment, the process further comprises regenerating the waste resin.

vi.Concentrating and combining

According to a further step of the method (step d), the low aromatic aqueous coffee extract having the second acrylamide content is combined with the high aromatic aqueous coffee extract to provide a liquid coffee concentrate. The two coffee extracts are usually combined by simple mixing.

As mentioned elsewhere herein, in embodiments wherein the initial aqueous extraction step is conducted at a temperature of less than 170 ℃ to obtain the additional aromatic aqueous coffee extract, the additional aqueous coffee extract may be combined with the high aromatic aqueous coffee extract and the low aromatic aqueous coffee extract having the second acrylamide content.

As mentioned elsewhere herein, in embodiments wherein the dearomatized roast and ground coffee has been subjected to multiple extraction steps and the multiple extracts are separated into a low aromatic aqueous coffee extract and an additional high aromatic aqueous coffee extract, the additional high aromatic aqueous coffee extract may be combined with the high aromatic aqueous coffee extract of step (b) and the low aromatic aqueous coffee extract having the second acrylamide content.

In certain embodiments, the method further comprises the step of concentrating the low aromatic aqueous coffee extract having the second acrylamide content prior to the combining step. In other words, the method may comprise the additional step between step c) and step d): concentrating the low aromatic aqueous coffee extract having the second acrylamide content. Such extracts may need to be concentrated in order to achieve the desired level of soluble coffee solids. For example, the extract containing 2 to 20 wt% soluble coffee solids is then concentrated, for example by evaporation, by freeze concentration or by filtration, until a concentration of 30 to 55% solids is reached. Preferred concentrates comprise from 6 to 80 wt% coffee solids, preferably from 10 to 65 wt%, more preferably from 15 to 50 wt%.

Concentrates are distinguished from extracts by being subjected to a number of water removal steps, such as water evaporation. Concentration methods such as evaporation, freeze concentration and filtration are well known to those skilled in the art. Preferably, the step of concentrating the low aromatic aqueous coffee extract having the second acrylamide content is performed in an evaporator unit.

The recovered high aromatic aqueous coffee extract may then be combined with a concentrated low aromatic aqueous coffee extract having a second acrylamide content to form a liquid coffee concentrate. This improves the flavor of the extract without compromising the solids level. Furthermore, it is advantageous to concentrate the low aromatic extract before combining the concentrated extract with the high aromatic extract in order to preserve the aroma in the high aromatic extract, which aroma might otherwise be lost during the concentration step.

Accordingly, in one embodiment, there is provided a process for producing a liquid coffee concentrate, the process comprising the steps of:

b) providing a high aromatic aqueous coffee extract;

c) contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having an adsorption function to provide a low aromatic aqueous coffee extract having a second acrylamide content;

d) concentrating the low aromatic aqueous coffee extract having the second acrylamide content; and

e) combining a concentrated low aromatic aqueous coffee extract having a second acrylamide content with a high aromatic aqueous coffee extract to provide a liquid coffee concentrate,

In case a fraction (e.g. at least 50%) of the low aromatic aqueous coffee extract has been subjected to the acrylamide reduction step (step c), the untreated low aromatic aqueous coffee extract may be combined with the treated low aromatic aqueous coffee extract (i.e. before concentration) or combined with the treated and concentrated low aromatic aqueous coffee extract (i.e. after concentration).

As mentioned elsewhere herein, the highly aromatic aqueous coffee extract obtained from the aroma restoration process may be stored for later use. Preferably, the highly aromatic aqueous coffee extract is cooled and stored at a temperature below 25 ℃, more preferably below 10 ℃, most preferably below 0 ℃. After storage, the high aromatic aqueous coffee extract may be added directly to the concentrated low aromatic aqueous coffee extract having the second acrylamide content without further treatment. Preferably, the high aromatic aqueous coffee extract is stored and cooled as briefly as possible, preferably under an atmosphere of an inert gas such as nitrogen, before being combined with the concentrated low aromatic aqueous coffee extract having the second acrylamide content. As a result of these steps, the loss of aroma and the degradation of aroma is limited as much as possible.

vii.Drying

According to further embodiments of the present invention, the method may further comprise the steps of: drying, thereby producing a soluble coffee product. In certain embodiments, the soluble coffee product is a soluble powder. Preferably, the drying step is freeze-drying as this helps to preserve the preserved flavour profile of the product. Preferably, the particle size of the powder product is from 200 to 3000 microns. Spray drying may also be used as a drying method.

viii.Liquid coffee concentrate/soluble coffee product

In a further aspect, the present invention provides a liquid coffee concentrate or soluble coffee product obtainable according to the method described herein. Liquid coffee concentrates and/or soluble coffee products are distinguished from other coffee concentrates and soluble coffee products in view of their reduced acrylamide content. For example, in certain embodiments, the acrylamide levels of the liquid coffee concentrates obtainable according to the methods described herein are reduced by 2% to 50% compared to untreated products. In another embodiment, the soluble coffee product obtainable according to the process described herein has less than 2% -50% acrylamide compared to an untreated product.

C：Carbon and/or silica-based resin having adsorption function for reducing content of low aromatic water-based coffee extract Use of enamide content

In another aspect of the present invention, there is provided the use of a carbon and/or silica based resin having an adsorption function for reducing the acrylamide content of a low aromatic aqueous coffee extract. In certain embodiments, there is provided the use of a carbon and/or silica-based resin having an adsorption function for reducing the acrylamide content of a low aromatic aqueous coffee extract, wherein the carbon and/or silica-based resin having an adsorption function is selective for acrylamide. In other words, a carbon and/or silica based resin having an adsorption function is provided for separating and/or extracting acrylamide from an aqueous coffee extract.

According to the present invention, a carbon and/or silica-based resin having an adsorption function is used to reduce the acrylamide content of a low aromatic aqueous coffee extract. As explained elsewhere herein, it is advantageous to subject the roasted and ground coffee beans to an aroma restoration process to preserve the aroma components. A low aromatic aqueous coffee extract may then be obtained and this low aromatic extract may be subjected to acrylamide reduction. This ensures that the acrylamide reduction process has a lower impact on the overall aroma and flavor profile of the coffee product compared to the prior art.

In certain embodiments, the use further comprises regenerating the waste resin. However, an additional advantage associated with the use of carbon and/or silica based resins having adsorption functionality as provided herein is that only the low aromatic aqueous coffee extract is in contact with the resin. This is in contrast to previous methods which have performed acrylamide reduction on the total aqueous coffee extract obtained from the extraction process. By contacting the carbon and/or silica based resin with adsorption function with a portion of the volume of extract, the resin lasts longer and does not need to be regenerated until later.

All embodiments described in relation to the first aspect of the invention are equally applicable to the further aspects of the invention.

For example, the adsorbent or porous ion exchange resin may be a carbon-based microporous adsorbent. Preferably, the ion exchange resin and/or adsorbent is

AF 5. In certain embodiments, the carbon and/or silica-based resin having adsorption functionality comprises a surface area between 700m ² G and 1500m ² A/g, more preferably between 900m ² G and 1500m ² Between/g, most preferably about 1200m ² Per gram of particles. Alternatively or additionally, the carbon and/or silica based resin with adsorption function comprises a pore volume of between 0.08cm ³ G and 0.2cm ³ Between/g, more preferably about 0.15cm ³ Particles of/gAnd (4) granulating.

In a preferred embodiment, the use comprises contacting the low aromatic aqueous coffee extract with a carbon and/or silica based resin having an adsorption function. In other embodiments, the use comprises contacting the low aromatic aqueous coffee extract with a carbon and/or silica-based resin having adsorption functionality for a time sufficient to reduce the acrylamide content of the low aromatic aqueous coffee extract. In a particular embodiment, the use comprises flowing the low aromatic aqueous coffee extract through a bed comprising a carbon and/or silica based resin having an adsorption function. In other embodiments, the use comprises flowing the low aromatic aqueous coffee extract through a bed comprising carbon and/or silica-based resins having an adsorption function for a time sufficient to reduce the acrylamide content of the low aromatic aqueous coffee extract. In certain embodiments, the acrylamide content is reduced by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or 100% as compared to the acrylamide content of the low aromatic aqueous coffee extract prior to contact with the carbon and/or silica-based resin having adsorption functionality.

Drawings

The invention will now be further described with reference to the following non-limiting figures.

Fig. 1 shows an exemplary flow chart of the method steps described herein.

The first step involves providing green coffee beans 5. These may be any suitable coffee beans 5, such as arabica coffee beans or robusta coffee beans, or mixtures thereof. The coffee beans are subjected to a roasting step 10 using conventional roasting methods to obtain the desired roasted coffee beans.

The roasted coffee beans are subjected to a grinding step 15. Grinding is usually carried out using a roller or burr type grinder, the final particle size and distribution being selected according to the subsequent extraction step. For example, percolation extraction systems tend to rely on average particle sizes of about 2 microns, whereas slurry-based processing systems may facilitate finer particle sizes, such as down to about 300 microns.

The roast and ground coffee is then subjected to an aroma restoration step 20, such as involving passing steam through the roast and ground coffee. The vapor is recovered and condensed to provide the high aromatic extract 25. The highly aromatic extract 25 is set aside for subsequent use, as described below, or may be used directly in a continuous process where all steps are performed in parallel. Roast and ground coffee that has been subjected to an aroma restoration step is dearomatized by this process.

The dearomatized roast and ground coffee is then passed to a primary extraction step 30 in which hot water is passed through the roast and ground coffee under pressure so that the water is at a temperature of from 100 ℃ to 170 ℃. This results in a primary extract 35 with good flavor profile (despite low yield) and low caloric yield markers.

The roast and ground coffee is then passed to a secondary extraction step 40 in which hot water is passed through the roast and ground coffee under pressure so that the water is at a temperature of 140 ℃ to 230 ℃. This produced a secondary extract 45 with reasonable flavor profile and good yield, but with moderate levels of heat yield markers, including acrylamide.

The roast and ground coffee (so-called spent coffee) after the secondary extraction step 40 may be passed to a tertiary extraction step 50. This is typically hotter and longer than the secondary extraction step 40 in the temperature range of 200 ℃ to 260 ℃. The roast and ground coffee after this step will be waste products, optionally burned to obtain thermal energy. The tertiary extract 55 from this tertiary extraction step 50 also exhibits a certain amount of acrylamide.

The methods described so far provide four extracts (25,35,45, 55). The tertiary extract 55 and, if desired, the secondary extract 45, which is a low aromatic extract, are then treated with a carbon and/or silica-based resin having an adsorption function in an acrylamide reduction step 60 to reduce the level of acrylamide in the product. The high aromatic extract 25 and the primary extract 35 are not subjected to the acrylamide reduction step 60 in order to avoid loss of volatile flavor components.

The process optionally involves a concentration step 65. This can be done on any of the extracts (35,45,55) to increase the solids of the extract. If desired, the secondary and tertiary extracts may be concentrated prior to the acrylamide reduction step 60 to reduce the volume of extract to be treated.

The method involves a mixing step 70. This involves blending the highly aromatic extract 25 with other extracts (35,45, 55). The extracts may be blended simultaneously or sequentially. The mixing step 70 may be performed before or after any optional concentration step 65.

The product of the mixing step 70 is a concentrated liquid coffee extract 75 that is suitable for reconstitution with hot water to form a coffee beverage. Alternatively, the concentrated liquid coffee extract 75 may be dried, such as by spray drying or freeze drying, to produce instant coffee powder 80.

The invention will now be further understood with reference to the following non-limiting examples.

Example 1

As depicted in figure 1, a high aromatic coffee extract was extracted from a single batch of roast and ground robusta coffee, which accounted for 84 wt% of total coffee dry matter.

The roasted and ground coffee was further extracted to obtain a secondary extract representing a low aromatic extract with a yield of 16% by weight of total coffee dry matter. The resulting acrylamide level in the secondary extract was 2200 μ g/kg based on dry solids.

Subsequently passing the secondary extract through a tightly packed resin material

The residence time on the resin is between 100s and 110 s. The acrylamide concentration of the resin-treated secondary extract was 1100. mu.g/kg, based on dry solids, which translates to a minimum 50% reduction in the acrylamide concentration in the secondary extract.

The secondary extract was then mixed with the high aromatic aqueous coffee extract at a weight ratio of 5:1 and concentrated to obtain a final liquid coffee concentrate having a 55 wt% solids level (i.e., 55 wt% of the concentrate was solids when fully dehydrated).

The concentrate was evaluated by a coffee specialist and found to have less impact on flavor. The total acrylamide reduction in the final product was 10%.

Example 2

A mixture of 30% arabica and 70% robusta coffee was roasted and ground. The resulting roast and ground coffee is extracted by split-stream extraction (as described in reference to WO 2007/043873) to obtain an aroma-rich extract, a primary extract and a secondary extract.

The aroma-rich extract is a high aromatic coffee extract and remains untreated. The aroma-rich extract accounted for 56 wt% of the total coffee dry matter. The acrylamide level obtained was 800. mu.g/kg, based on dry solids.

The primary extract is significantly less fragrant than the aroma-rich extract. The primary extract had an acrylamide level of 1300 μ g/kg based on dry matter solids. The primary extract accounted for 27 wt% of the total coffee dry matter.

50% of the primary extract remained untreated, and 50% of the extract was passed alone through the tightly packed resin material

AF5, the residence time of the extract on the resin is between 100s and 110 s. The resulting acrylamide level in the treated primary extract was less than 600 μ g/kg based on dry matter solids.

Additional low aromatic secondary extracts are obtained from roast and ground coffee obtained after the primary extract by additional extraction methods as described in step 40 of fig. 1. The secondary extract had an acrylamide level of 2100 μ g/kg and a yield of 17 wt% of total coffee dry matter, based on dry matter solids.

100% of the secondary extract is passed through the tightly packed resin material

AF5 column, the retention time of the extract on the resin is between 100s and 110 s. The resulting treated secondary stage based on dry matter solidsThe extract has an acrylamide level of less than 1100 μ g/kg, which is a minimum 50% reduction in conversion to acrylamide.

The 100% treated low aromatic secondary extract was then combined with the untreated primary extract and untreated aroma-rich extract to obtain the final total extract, on which the acrylamide content was measured. The results of acrylamide reduction of this final total extract are reported in table 1, line 1 (22%).

In another sample, 50% of the treated primary extract was combined into 100% of the treated secondary extract and the remaining untreated primary extract to obtain the final recombined extract, on which the acrylamide content was measured. Table 1, line 2 shows the acrylamide reduction results (25%) for this final recombined extract.

The reduction in acrylamide levels in the final product resulting from the combination of the two extracts was 25%. The acrylamide reduction of the combined final extracts was determined by HPLC by standard methods for determining acrylamide concentrations.

The aroma-rich extract was then mixed with the primary and secondary extracts in a weight/weight ratio of 56/27/17 wt% of total coffee dry matter.

Evaluation of the flavour profile was performed via gas chromatography selecting key flavour compounds. Limited impact on flavor was found (see table 1).

The resulting combined final extracts were then evaporated to a DM of 55% to obtain a concentrate. The concentrate is filled into the final product and/or dried and filled as soluble coffee. The concentrates were evaluated by coffee experts and found to have limited impact on flavor in the final product.

Example 3

As described in example 1, in

The low aromatic aqueous coffee extract obtained by extracting roast and ground coffee as described in fig. 1 was treated on AF5 resin resulting in a 50% reduction of acrylamide on the treated low aromatic aqueous coffee extract.

In addition, the primary extract obtained by the primary extraction of step 30 of FIG. 1 and having an acrylamide level of 1000ug/kg based on dry solids is only partially in the tightly packed resin material

Treating on AF, wherein the residence time of the extract and the resin is between 100s and 110 s. After treatment on the resin, the treated fraction of the primary extract is recombined with the untreated fraction of the primary extract and mixed with the low aromatic extract (i.e., the fully treated secondary extract) in combinations of different ratios, i.e., they provide a mixture of treated primary extract, untreated primary extract and treated secondary extract.

For both extracts, the acrylamide concentration of the resin-treated primary extract was less than 500 μ g/kg on a dry solids basis, which resulted in a minimum of 50% reduction in acrylamide for each extract.

The treated and untreated primary extracts were then mixed with the low aromatic coffee extract on a 5:1 weight basis and concentrated as described above to obtain the final liquid coffee concentrate.

After freeze-drying, the final product was analyzed. Rows 1 and 2 of table 2 report the results of acrylamide reduction in the final concentrate with 40% fraction of treated primary extract and 60% fraction of treated primary extract (columns 1 and 2 of table 2). Only for the 40% primary extract treated samples, reductions in the range of 38 to 54 had limited impact on flavor.

The concentrates were evaluated by a coffee specialist, acrylamide levels were determined by HPLC, and aroma was analyzed by gas chromatography.

To provide comparative data, the inventors also investigated the effect of treating the primary extract.

Comparative example

A single batch of ground robusta coffee as described in example 1 was extracted via a single extraction pass. The extraction produced a high aromatic coffee extract, 84 wt% of total coffee dry matter. After the first extraction, the dearomatized coffee is further extracted to obtain a low aromatic aqueous extract of 16% by weight of the total coffee dry matter. The latter had an acrylamide level of 2200ug/kg on a dry solids basis.

The high aromatic extract and the low aromatic extract were combined at a weight/weight ratio of 5: 1.

Use of

AF-5 to treat the combined extracts. The treated extract was concentrated as described above to obtain the final concentrate and evaluated by coffee experts, determining acrylamide levels via HPLC analysis and analyzing key aroma compounds by gas chromatography. A significant impact on flavor was found in the final product, with a 100% reduction in aroma and a 91% reduction in acrylamide. As will be appreciated, the processing time and complexity of processing the entire extract is significant.

The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims. Moreover, all aspects and embodiments of the invention described herein are to be considered broadly applicable and combinable with any and all other consistent embodiments, including those taken from other aspects of the invention (including individually) where appropriate.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Various publications and patent applications are cited herein, the disclosures of which are incorporated by reference in their entirety.

Claims

1. A method for producing a liquid coffee concentrate, the method comprising the steps of:

b) providing a high aromatic aqueous coffee extract;

d) combining the low aromatic aqueous coffee extract having a second acrylamide content with the high aromatic aqueous coffee extract to provide a liquid coffee concentrate,

2. A process according to claim 1, wherein the process comprises subjecting roast and ground coffee to an aroma restoration process to obtain:

(i) the highly aromatic aqueous coffee extract; and

(ii) dearomatized roast and ground coffee.

3. The method according to claim 2, wherein the aroma restoration method comprises contacting the roast and ground coffee with steam and obtaining the highly aromatic aqueous coffee extract from the steam.

4. The process according to claim 2 or claim 3, wherein the low aromatic aqueous coffee extract having a first acrylamide content is obtained by aqueous extraction of the dearomatized roast and ground coffee, wherein the aqueous extraction is carried out at a temperature above 140 ℃, preferably from 140 ℃ to 230 ℃.

5. The process according to claim 2,3 or 4, wherein the low aromatic aqueous coffee extract having a first acrylamide content is obtained by the aqueous extraction of dearomatized roast and ground coffee, preferably wherein the aqueous extraction is carried out at a temperature of from 200 ℃ to 260 ℃.

6. The process according to claim 2,3, 4 or 5, wherein before obtaining the low aromatic aqueous coffee extract with a first acrylamide content by aqueous extraction of the dearomatized roast and ground coffee, the dearomatized roast and ground coffee is subjected to an initial aqueous extraction at a temperature below 170 ℃, preferably between 100 ℃ and 170 ℃, to obtain a further aromatic aqueous coffee extract which is combined in step d) with the low aromatic aqueous coffee extract with a second acrylamide content and the high aromatic aqueous coffee extract to provide the liquid coffee concentrate.

7. The method of any of the preceding claims wherein the method further comprises the step of concentrating the low aromatic aqueous coffee extract having a second acrylamide content.

8. The method according to any one of the preceding claims, wherein contacting the low aromatic aqueous coffee extract with a carbon and/or silica based resin having an adsorption function comprises flowing the low aromatic aqueous coffee extract through a bed comprising the resin.

9. The method of any one of the preceding claims, wherein the resin has a size exclusion function.

10. The method of any one of the preceding claims, wherein the method further comprises regenerating spent resin.

11. The process according to any one of the preceding claims, wherein the carbon and/or silica-based resin having an adsorption function comprises a surface area of between 700m ² G and 1500m ² Between/g, preferably about 1200m ² Per gram of particles.

12. The process according to any one of the preceding claims, wherein the carbon and/or silica based resin having an adsorption function comprises a pore volume of between 0.08cm ³ G and 0.2cm ³ Between/g, preferably about 0.15cm ³ Per gram of particles.

13. The method of any preceding claim wherein the second acrylamide content is at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or 100% lower than the first acrylamide content.

14. The method according to any of the preceding claims, further comprising the step of: drying the liquid coffee concentrate, thereby producing a soluble coffee product.

15. A liquid coffee concentrate obtainable according to the process of any one of claims 1 to 13, or a soluble coffee product obtainable according to the process of claim 14.

16. A liquid coffee concentrate or soluble coffee product according to claim 15 having a reduced level of acrylamide in the final product of 2-50% by weight.

17. Use of a carbon and/or silica-based resin having an adsorption function for reducing the acrylamide content of a low aromatic aqueous coffee extract, wherein the carbon and/or silica-based resin having an adsorption function is selective for acrylamide.